Non-lethal devices and diversionary devices, such as so-called “flash-bang” devices, are used by military, law enforcement, security and other personnel to provide diversions or initial stages in escalation of force in combat or operational situations or to provide demonstrations and simulated combat conditions during training. When activated, the non-lethal devices or diversionary devices deliver a flash of light and sound to an area surrounding the activated device. The level of light and sound output is designed to temporarily incapacitate people within the proximity of the activated device with a calculated risk of permanent injuries depending on the given stage in the escalation of force. The flash of light (e.g., a fireball) may temporarily blind a person viewing the fireball, and the sound or pressure impulse produced by the device may incapacitate a person's auditory capabilities. The desired effect of the non-lethal device is to temporarily distract or incapacitate people within a general vicinity of the device when the device is activated. Ideally, the device does not permanently injure or fatally wound the people exposed to the effects of an activated device. With these goals in mind, non-lethal or less than lethal devices have been developed to deliver the desired fireball area as well as integrated light output (flash) and corresponding pressure impulse (bang).
Legacy flash/bang formulations used in non-lethal devices are designed primarily to produce a pressure impulse to warn, divert attention, or cause a temporary threshold shift in the hearing of a person. The legacy flash/bang formulations include a powdered oxidizer, such as a perchlorate-based oxidizer, in combination with a metal, such as magnesium or aluminum. Magnesium and aluminum have been used as the metal that is the primary source of the light output upon its oxidation whereas the presence of the perchlorate-based oxidizer blended with the metal promotes oxidation of the metal within milliseconds, very rapidly producing heat and concomitant gas expansion in the form of a pressure impulse.
U.S. Pat. No. 8,172,966 describes a non-lethal payload that includes an igniter/activator and an illuminant. When initiated, the igniter/activator produces a sufficiently high temperature to initiate the illuminant. The igniter/activator includes a granular composition of boron/potassium nitrate (B/KNO3), a granular composition of magnesium strontium nitrate (Mg/Sr(NO3)2), or a combination of B/KNO3 and Mg/Sr(NO3)2. The igniter/activator includes a binder to facilitate the handling or production of the igniter/activator. The illuminant includes a powdered metal, such as powdered aluminum or powdered magnesium and, optionally, an oxidizer. In some configurations, the illuminant is fuel rich and relies on the reaction of the powdered metal with oxygen in the air. Many of these configurations produce a significantly greater integrated light output than legacy flash/bang formulations. Because light evolution is dependent, at least in part, upon oxidation of the powdered metal with air, flash duration may extend beyond 100 milliseconds. It has been determined that while these non-lethal payloads are effective, a non-lethal payload including only a powdered metal as the illuminant was not efficient because either the non-lethal payload was not totally dispersed upon initiation, or the reaction of the powdered metal was quenched before complete combustion occurred.
Pyrotechnic formulations including boron, such as the granular composition of the igniter/activator described above, have conventionally been produced using a binder, such as a polymer. Granules of the igniter/activator are produced by dissolving the binder in a solvent, wetting the other dry ingredients of the igniter/activator with the solvent by a slurry mixing process, evaporating the solvent, and granulating the wet paste. The wet paste is dried and then dry granulated to produce the granular form of the B/KNO3 component of the igniter/activator. The granular Mg/Sr(NO3)2 component of the igniter/activator is produced in a similar manner. However, the B/KNO3 and Mg/Sr(NO3)2 of the igniter/activator tend to segregate after these components are combined. The segregation of the components of the igniter/activator may be viewed visually where agglomerations of the B/KNO3 are brown in color and those of Mg/Sr(NO3)2 are silver in color. Agglomerations, indicating the segregation of the components of the igniter/activator, may also be determined by chemical analysis. Thus, the igniter/activator prepared by the granulation process may be a heterogeneous material including agglomerations of boron and potassium nitrate, agglomerations of magnesium and strontium nitrate, and/or agglomerations of boron, potassium nitrate, magnesium, and strontium nitrate.
Processing of a granular igniter/activator is time and labor intensive due first to the labor intensive slurry mixing, wet granulation, drying, and dry granulation process described above. Additional labor is also used to blend and load the granular B/KNO3 and granular Mg/Sr(NO3)2 components of an igniter/activator into a device in a manner that promotes a consistent blend ratio from one device to the next, and mitigates desegregation of components once loaded. It would be desirable to produce a non-lethal payload that provides a desired light and sound output by a less labor and time intensive process.